Compact liquid converter assembly

ABSTRACT

An electronic converter assembly including a liquid cooled heat sink member having a sink length dimension, at least one mounting surface and first and second oppositely facing lateral surfaces, the mounting surface and first and second lateral surfaces forming first and second lateral edges, respectively, the sink member also forming at least one internal channel that extends substantially along the entire sink length, an inlet and an outlet that open into opposite ends of the channel, a plurality of power switching devices mounted side by side to the mounting surface thereby forming a single device row that extends substantially along the sink length, each device including intra-converter terminals that are substantially within a single connection plane, a plurality of capacitors, each capacitor including capacitor connection terminals, the capacitors linked for support to and adjacent the sink member with the capacitor terminals juxtaposed substantially within the connection plane and a linkage assembly including a plurality of conductors that link the capacitor terminals to the intra-converter terminals to form a power conversion topology.

CROSS-REFERENCE TO RELATED APPLICATIONS

Not applicable.

STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT

Not applicable.

BACKGROUND OF THE INVENTION

The field of the invention is power converters and more specificallyconverter configurations including heat sinks that reduce the overallspace required to accommodate the configurations.

It is well known that variable speed drives of the type used to controlindustrial electric motors include numerous electronic components. Amongthe various electronic components used in typical variable-speed drives,all generate heat to a varying degree during operation. Typically,high-power switching devices such as IGBTs, diodes, SCRs and the like aswell as storage devices such as capacitors are responsible forgenerating most of the heat in a variable-speed drive. It is for thisreason, therefore, that most variable-speed drives include a heatsink(s) upon which the power switching devices are mounted. The heatsink(s) conducts potentially damaging heat from assembly components.

Selecting the size and design of a heat sink for a particular variablespeed drive is somewhat of a challenge. First, a designer must be awareof the overall characteristics of the motor and drive pair. Second, thedesigner must understand the industrial application in which the motorand drive pair will be used, including the continuous and peak demandsthat will likely be placed on the motor and drive by the load. Third,the designer must accommodate, in the design, certain unexpectedconditions that would deleteriously affect the heat transfer capabilityof the heat sink such as unexpectedly high ambient temperatures,physical damage to the heat sink such as mechanical damage, or a buildup of a debris layer, as examples. Fourth, the heat sink(s) must bephysically dimensioned so as to fit into the space allotted per customerrequirements, cabinet or enclosure size, or the like.

In the past, air-cooled heat conducting plates were used to transferthermal energy from electronic parts to the ambient air. These werepassive heat-transfer devices and were generally formed of alight-weight aluminum extrusion including a set of fins. As a generalrule, heat transfer effectiveness is based on the temperaturedifferential between the power devices and the ambient air temperature.Of course, in order to provide adequate heat conduction, heat sinks ofthis type oftentimes are necessarily large and, therefore, bulky andexpensive. If high ambient conditions exist, the heat sink becomesineffective or useless as heat removal cannot be accomplished regardlessof the size of the heat sink. If the variable speed drive was in anenclosed space the heat removed from the drive would need to beexhausted or conditioned for recirculation.

By forcing air over fins defined on the heat-conducting plate (e.g., analuminum extrusion), improved cooling efficiency can be realized. Largeblower motors are often used for this purpose. However, as the finsdefined in the aluminum extrusions become dirty or corroded during use,the heat sinks become less effective or useless altogether. Blowermotors cannot be used in environments where air cleanliness would clogfiltration. Therefore, air conditioning equipment is often added tointernally circulate and cool the air that is passed over the heat sinkfins.

Liquid cooled heat sinks or cold plates have also been used for someapplications but with limited success. Generally, a liquid cooled heatsink includes a series of chambers or channels that are formedinternally within a sink body member that is formed of material (e.g.,copper or aluminum) that readily conducts heat. The body member includesat least one mounting surface for receiving heat generating devices. Thechannels are typically configured so that at least one channel sectionis formed adjacent each surface segment to which a heat generatingdevice is mounted—typical channel configurations are serpentine. Acoolant liquid is pumped through the channels from one or more inletports to one or more outlet ports to cool the sink member and henceconduct heat away form the heat generating devices.

The industry has developed several ways in which to manufacture liquidcooled heat sinks and, each of the different ways to manufacture hasdifferent costs associated therewith. For instance, a liquid cooled sinkcan be constructed by forming a desired serpentine copper conduit pathfor liquid flow, placing the serpentine conduit construct within a sinkmold, pouring molten liquid aluminum into the mold and allowing themolten aluminum to cool. While this manufacturing process has been usedsuccessfully, liquid molding processes are very difficult to control andthe incidences of imperfect and or non-functioning product have beenrelatively high.

One other sink manufacturing process that has proven useful includescutting a at least one channel out of a sink body member, hermeticallysealing (e.g., vacuum brazing) a cover member to the body member tocover the channel and then forming an inlet and an outlet that open intoopposite ends of the channel. This two part sealing process is much lessexpensive than the conduit-molten process described above.

When designing any liquid cooled heat sink several factors have to beconsidered including heat dissipating effectiveness, volume required toaccommodate a resulting converter, and cost. With respect to heatdissipation, in the case of a power conversion assembly, there aretypically several different heat generating devices that are similarlyconstructed and that operate in a similar fashion to convert power. Forinstance, as well known in the controls arts, an AC to DC rectifiertypically includes a plurality of power switching devices that arearranged to form a bridge assembly. In the case of a three phase supplyand load, the bridge assembly includes three phases, a separateswitching phase for each of the three supply and load phases. Here, anexemplary phase may include first and second power switching deviceslinked at a common node to an associated supply line where the otherterminals of the first and second switches are linked to positive andnegative DC busses, respectively. A controller is configured to controlall of the three phases of the bridge together to convert the threephase AC supply voltage to a DC potential across the positive andnegative DC busses.

In a similar fashion, a three phase inverter assembly typically includesthree separate phases that link positive and negative DC busses to threeload supply lines. In the case of an inverter, each phase typicallyincludes first and second power switching devices that are linked inseries between the positive and negative DC busses with the common nodebetween the first and second inverter switches linked to an associatedphase of the load. Where the supply and load voltages are large, somerectifier/inverter converter assemblies may include several three phasebridges linked together thereby reducing the load handling of eachswitching device.

In the case of a rectifier-inverter conversion assembly, a drive circuitis provided that controls all of the switching devices together tocreate desired three phase output voltages to drive a load linkedthereto. In this case, it is imperative that the switching devicesoperate in characteristic and substantially similar ways to simplifywhat is, by its very nature, an already complex switching scheme. Forthis reason, converter designers typically select switching deviceshaving known operating characteristics to configure their conversionassemblies.

Nevertheless, as also well known, most switching devices have operatingcharacteristics that are, at least in part, affected by the environmentsin which the devices operate. Specifically, for the purposes of thepresent invention, it should be appreciated that switching deviceoperating characteristics change as a function of temperature. Forinstance, an internal switch resistance has been known to change as afunction of temperature which in turn affects the voltage drop acrossthe switch. While each voltage drop change that occurs may seeminsignificant, because rectifier and inverter switches are typicallyturned on and off very rapidly, the affect of changing device drop hasbeen shown to be appreciable.

The problems associated with voltage drop variance are compounded wheresimilar switching devices are operated at different temperatures and isespecially acute where control schemes operate to simultaneously controlall three conversion assembly phases together to generate load voltages.Thus, for instance, where one switching device is several degrees hotterthan another switching device, the result may be unbalanced phasevoltages and hence imperfect load control (e.g., non-smooth motorrotation) which increases overall system wear and can cause systemdamage over time.

For this reason, one challenge when designing a heat sink for use with aconverter assembly has been to provide essentially identical heatdissipating capacity to each converter switching device so that devicetemperatures are essentially identical during system operation. Theproblem here is that coolant temperature rises as the coolant absorbsheat along its path through a sink member so that power switchingdevices relatively near an inlet port along a serpentine coolant pathare cooled to a greater degree than switching devices down stream fromthe inlet port. One solution that reduces the heat dissipating capacitydifferential between similar switching devices has been to provide aheat sink where the spacing between a cooling liquid inlet and each ofthe sink surfaces to which switching devices are mounted is similar. Forinstance, where a configuration includes twenty four power switchingdevices, instead of mounting the switching devices to the sink in apattern that tracks a single serpentine cooling conduit path, theswitching devices may be mounted on sink member mounting surface to formsix rows of four switching devices each where each of the six rows isfed by a separate one of six liquid coolant inlet ports—here a manifoldmay serve each of the six inlet ports (see generally FIG. 23 in U.S.Pat. No. 6,031,751 (hereinafter “the '751 patent”) entitled “SmallVolume Heat Sink/Electronic Assembly” which issued on Feb. 29, 2000 andwhich is incorporated herein by reference). Thus, in this case, coolantfrom each of the six inlet ports passes by four separate heat generatingdevices and device cooling will be relatively more uniform. Thissolution to reduce the device temperature differential will be referredto hereinafter as a matrix spacing solution.

One other solution that reduces the heat dissipating capacitydifferential between switching devices mounted to a sink member has beento provide a serpentine path that passes by each heat generating devicemore than once so that the overall cooling affect of devices is similar.For instance, assume twelve switching devices are mounted to a sinkmember mounting surface to form two rows of six devices each and that asingle serpentine path is configured to include a first linear run thatpasses adjacent the first row of devices, a first 180 degree turn, asecond linear run that passes adjacent the second row of devices, asecond 180 degree turn, a third linear run that again passes adjacentthe second row of devices, a third 180 degree turn and a fourth linearrun that passes a second time by the first row of devices to an outlet.

Here, in theory, the first linear run should include the coolestcoolant, the second linear run should include the second coolest coolantand so on so that the coolant temperatures through the first and fourthlinear runs (i.e., adjacent the devices in the first row) should averageand the coolant temperatures though the second and third linear runs(i.e., adjacent the devices in the second row) should also average andthe two average temperatures should be similar (see generally FIG. 2 inthe '751 patent). This solution to reduce the device temperaturedifferential will be referred to hereinafter as an averaging solution.

While the averaging solution and the matrix spacing solution work intheory, in reality, each of these solutions have had some problemsregarding temperature differential. With respect to the matrix spacingsolution, in the example above, the fourth device along each of the sixseparate coolant paths is warmer than the first device along the samepath as liquid passing by the first three devices along the path heatsup when heat is absorbed along the path. Thus, while better than sinksthat align devices along a single serpentine cooling conduit path, thematrix solution still results in a temperature differential.

With respect to the averaging solution, it has been determined that,despite multi-pass designs, at least some temperature differential stillexists between devices spaced at different locations along the coolantconduit path. In addition, in some cases, cooling capacity may vary overthe heat dissipating surface of each heat generating device. Thisintra-device dissipating differential may occur as a multi pass pathnecessarily requires that the coolest pass (i.e., the first pass by adevice) be positioned along one side of a dissipating surface so thatanother one or more passes that include relatively warmer coolant can bepositioned along the other side of the dissipating surface.

With respect to volume (i.e., the second factor above to consider whendesigning a heat sink), as with most electronics designs, all otherthings being equal, smaller is typically considered better. Thus, someprior converter configurations have provided sink members that eitherfacilitate stacking of relatively short devices adjacent elongateddevices (see FIG. 19 in the '751 patent) or, in the alternative,aligning similar dimensions of different devices (see FIG. 13 in the'751 patent).

For instance, the '751 patent recognizes that, in addition to powerswitching devices, converter configuration capacitors also oftengenerate excessive heat that should be dissipated to ensure properoperation. The '751 patent also recognizes that capacitors typicallyhave a length dimension perpendicular to their heat dissipating surfacethat is much longer than the thickness dimensions of typical switchingdevices perpendicular to the device dissipating surfaces and that theswitching devices typically have a length dimension that is similar tothe capacitor length dimension. In this case, in one embodiment, the'751 patent recognizes that overall converter configuration size can bereduced by providing an L shaped sink member having two legs that form a90° angle, mounting the capacitors to an inside surface of one of thelegs and within the space defined by the two leg members and mountingthe switching devices to the outside surface of the other of the legmembers thereby aligning the similar capacitor and device lengthdimensions.

With respect to cost, unfortunately, where an L shaped heat sink memberor, for that matter, where a sink member having sections that residealong other than a single plane is required to stack or align capacitorswith switching devices, the relatively inexpensive two part sealingprocess described above becomes much more difficult to use. This isbecause the two part sealing process generally includes vacuum sealing aflat cover member over a channel forming body member, When the channelmust reside in more than one plane and requires a more complex covermember, tolerances required to provide a suitable cover member would beextremely difficult to meet and the sealing process would be difficultto perform effectively.

Thus, where the sink member must reside in two or more planes tofacilitate stacking and/or aligning, the more expensive molten-conduitprocess would likely be employed where the conduit is formed into thedesired channel shape and molten aluminum or the like is poured into amold there around. For this reason prior stacking and aligningconfigurations have proven to be relatively expensive to manufacture andoften are not suitable given cost constraints.

Also, with respect to cost, often the last converter designconsideration is how system components will be electrically linkedtogether to form a converter topology. One particularly advantageous androbust type of linking assembly is referred to generally as a laminatedbus bar. As its label implies, a laminated bus bar typically includes aplurality of metallic sheets of laminate that are layered together withinsulators between adjacent laminate sheets. Vias are formed within thelaminated assembly where links are to be made to capacitor and switchingdevice terminals. The vias automatically link the devices and capacitorsup in a desired fashion to provide an intended converter topology (e.g.,rectifier, inverter, rectifier-inverter, etc.).

Laminated bus bar cost is generally a function of the amount of materialrequired to construct the bus, the number of laminate layers required tosupport a configuration and the overall complexity of the requiredlaminate member where minimal material, minimal layers and minimalcontours (i.e., bends in the laminates) are all advantageous.Unfortunately, providing a configuration that uses minimal laminatematerial, requires minimal layering and restricts the laminate to asingle plane is extremely difficult given the sink member configurationsrequired to minimize overall configuration size and provide essentiallyuniform heat dissipating capacity to all switching devices mounted tothe sink. For example, where devices are arranged in rows and columns toprovide similar distances between channel inlets and devices down streamtherefrom, typically a large number of laminate layers and acorrespondingly complex labyrinth of vias are required to linkcomponents together. As another instance, where switching device lengthsare aligned with similarly dimensioned capacitor lengths the laminationbus typically requires one or, more often, several bends to accommodateconnection terminals that reside in disparate planes. In either of thesetwo cases (i.e., many layers or several laminate bends) the amount ofmaterial required to configure a laminated bus bar can be excessive andhence unsuitable for certain applications.

Yet one other cost consideration related to converter configurations hasto do with component versatility or the ability to use convertercomponents in more than one converter configuration. Componentversatility is particularly important with respect to the more expensivecomponent types such as, for example, the heat sink assembly, thelaminated bus bar, etc. In this regard, overall system costs can bereduced by designing sinks and laminated bus bars that can be used withvarious device and capacitor types. For instance, assume that a firstconverter configuration includes a first type of switching device, afirst type of capacitor, a first type of sink member and a first type oflaminate bar. Also assume that the sink, devices and a capacitors aredimensioned such that when the capacitors and devices are mounted to thesink, the capacitors connection terminals are on the same plane as thedevice connection terminals. Here, the first laminate bus bar type canbe planar and hence relatively.

Next assume that a designer wants to swap out a second capacitor typefor the first type in the configuration where the second capacitor typehas a thickness between its dissipating surface and its connectionterminals that is different than a similarly measures thickness of thefirst capacitor type. In this case, when the capacitors are swapped, thecapacitor and device terminals will no longer reside within the sameplane and a different, perhaps custom designed, laminate will berequired to accommodate the change. In the alternative, the sink designmay be altered to accommodate the change in device and capacitorterminal planes although this solution would be relatively expensive.Similar problems occur when different switching devices are swapped intoconfigurations.

Thus, it would be advantageous to have a heat sink assembly that isrelatively inexpensive to manufacture and yet provides substantiallysimilar heat dissipating capacity to all devices mounted thereto. Inaddition, it would be advantageous if a sink assembly of the above kindcould be used with a simplified laminate design and be used to configurerelatively compact converter assemblies. Moreover, it would beadvantageous if the sink assembly could be versatile and hence used withother converter components that have many different dimensions.

BRIEF SUMMARY OF THE INVENTION

It has been recognized that relatively compact and inexpensive converterconfigurations can be configured by using an elongated liquid cooledheat sink to cool power switching devices. More specifically, it hasbeen recognized that, where switching devices are mounted in a singlerow to a sink member mounting surface, the sink can be used to configureminimal volume converter configurations. In at least one embodiment ofthe invention, the sink mounting surface has a width dimension that issubstantially similar to a width dimension of switching devices to bemounted thereto with the device width dimensions aligned with themounting surface width dimension. This single row limitation has severalconfiguration advantages described below.

It has also been recognized that, with certain types of refrigerant, thecooling capacity differential along a cooling channel appears to beexacerbated along the channel length. For instance, the cooling capacitydifferential appears to be relatively pronounced in the case of twophase refrigerants such as R-134a and R-123. As the label implies, twophase refrigerants change from a liquid to a gas when heat is absorbedand hence, generally, absorb a greater amount of heat, due to theendothermic nature of the phase change, than conventional single-phaseliquid refrigerants such as water -hence two phase refrigerants aregenerally preferred in high efficiency heat sinks.

Moreover, it has been recognized that, unfortunately, as two-phaserefrigerants absorb heat and change phase from liquid to gas, vaporbubbles are formed within the liquid that accumulate on the internalsurfaces of the heat sink and form gas pockets. The gas pockets on thesurface of the channel block refrigerant from contacting the channelsurface and hinder device heat absorption by the refrigerant. Thus, thechannel surfaces on which gas pockets form end up becoming hot spots onthe channel surfaces and the temperatures of devices attached adjacentthereto rise.

Because the vapor bubbles are formed by heat absorption and becausecoolant relatively further down stream from an inlet is warmer thancoolant more proximate the inlet, relatively more vapor bubbles areformed down stream from the inlet than proximate the inlet therebycausing more gas pockets to form down stream which increases thetemperature differential along the channel length. Thus, it has beendetermined that, while coolant temperature accounts for some of thetemperature differential along a coolant channel length, much of thetemperature differential is actually due to different amounts of gasaccumulating along different sections of the channel—the gas having aninsulating effect between the channel surfaces and the coolant passingthereby. Based on these realizations it should be appreciated that thetemperature differential problem is exacerbated where sink channels areextended.

According to several embodiments of the invention, protuberances of acharacter, quantity and size that increase turbulence within sinkchannels to a point where the turbulence either prohibits gas pocketsfrom forming on the channel surfaces or dislodges or breaks up gaspockets that form on the channel surfaces, are provided on at least oneof the channel surfaces. It has been found that when such protuberancesare provided within a channel, the channel can have an extended lengthwithout causing excessive temperature differentials there along. Morespecifically, it has been determined that the channel length can, in atleast one embodiment, extend substantially along an entire sink lengthwhere the sink, as indicated above, has a length to accommodate a singlerow of switching devices. For instance, where a converter configurationincludes twenty four switching devices, the twenty four devices can bearranged in a single row along the sink member mounting surface wherethe channel extends along substantially the entire sink length from aninlet to an outlet.

It has also been determine that, in at least some embodiments of theinvention, the sink member can be juxtaposed so that the channel inletis below the channel outlet and, more specifically, so that the channelinlet is directly vertically below the channel outlet. Here, dislodgedor broken up gas pockets, being lighter than the refrigerant, are aidedby buoyancy in their movement toward the outlet at the top of the sinkchannel.

By providing an elongated sink-device assembly including devices mountedin a single row to an elongated sink member, overall converter cost canbe reduced. In this regard, the single channel sink member can bemanufactured using the two piece sealing method described above wherethe channel is bore out of a body member, a cover member is hermeticallysealed over the channel and inlet and outlet ports that open into thechannel are formed.

In addition, cost is reduced with the inventive elongated sink-deviceassembly as a simplified laminated bus bar can be used with thesink-device assembly. In this regard, where capacitors are juxtaposed toone side of the switching devices and with capacitor terminals anddevice terminals positioned within a common connection plane, thedistances between capacitor terminals and the device terminals that thecapacitor terminals are to be linked to are reduced appreciably so thatless material is required to make terminal connections. Moreover,because capacitor terminals and the device terminals to which thecapacitor terminals are to be linked may be positioned proximate eachother, none of the laminates have to pass over other devices disposedintermediate the connecting terminals and therefore simpler laminate andassociated via designs can be employed that include relatively smallnumbers (e.g., 3) of laminate layers.

Consistent with the above, at least one embodiment of the inventionincludes an electronic converter assembly comprising a liquid cooledheat sink member having a sink length dimension, at least one mountingsurface and first and second oppositely facing lateral surfaces, themounting surface and first and second lateral surfaces forming first andsecond lateral edges, respectively, the sink member also forming atleast one internal channel that extends substantially along the entiresink length, an inlet and an outlet that open into opposite ends of thechannel, a plurality of power switching devices mounted side by side tothe mounting surface thereby forming a single device row that extendssubstantially along the sink length, each device includingintra-converter terminals that are substantially within a singleconnection plane, a plurality of capacitors, each capacitor includingcapacitor connection terminals, the capacitors linked for support to andadjacent the sink member with the capacitor terminals juxtaposedsubstantially within the connection plane and a linkage assemblyincluding a plurality of conductors that link the capacitor terminals tothe intra-converter terminals to form a power conversion topology.

In one embodiment each power switching device includes first and secondoppositely facing linking edges and wherein the intra-converterterminals form the first linking edge proximate the first lateral edgeof the sink member.

Some embodiments further include a bracket member mounted to the sinkmember and extending past the first surface, the capacitors mounted tothe bracket member for support. More specifically, the mounting surfacemay be a first mounting surface and the sink member may include a secondmounting surface that faces in a direction opposite the first mountingsurface wherein the bracket member is mounted to the second mountingsurface.

In some embodiments the bracket member includes a proximate membermounted to the second mounting surface, an intermediate member linked toand forming a substantially 90 degree angle with the proximate memberand extending substantially parallel to the first lateral side of thesink member and generally away from the sink member and a distal memberforming a substantially 90 degree angle with the intermediate member andextending generally away from the sink member, the capacitors mounted tothe distal member. Moe specifically, in one embodiment each of thedevices includes a heat dissipating surface adjacent the mountingsurface and is characterized by a device thickness dimension between theconnection plane and the dissipating surface of the device, the firstand second mounting surfaces are separated by a sink thickness, theintermediate member has an intermediate member length, each capacitorincludes first and second oppositely facing ends and a length dimensionbetween the first and second ends, the capacitor terminals extendaxially from the first end of each capacitor and the second end of eachcapacitor is mounted to the distal member and, wherein, the combinedsink thickness, device thickness and intermediate member length issubstantially similar to the capacitor length dimension.

Each capacitor may have a heat conducting extension that protrudes fromthe second end of the capacitor and that is in conductive contact withthe distal end of the bracket member. Here, the bracket member may beformed of a heat conducting material (e.g., aluminum or copper). Inaddition, here, the linkage assembly may include a substantially planarlaminated bus bar.

In some embodiments the linkage assembly links the capacitors and powerswitching devices together to form an inverter while in otherembodiments the linkage assembly may link the capacitors and switchingdevices to forma rectifier. In still other embodiments the linageassembly may link the capacitors and switching devices to form both arectifier and an inverter.

The first and second lateral edges of the mounting surface may form asink member width and a device width between the first and secondlinking edges may be substantially similar to the sink member width.

In some embodiments the channel inlet is disposed below the channeloutlet. More specifically, the channel inlet is substantially directlyvertically below the channel outlet. In some embodiments the extensionmembers may be provided that extend into the channel thereby increasingturbulence in liquid pumped from the inlet to the outlet.

The invention also includes an electronic converter assembly comprisinga heat sink member having a sink length dimension, at least one mountingsurface and first and second oppositely facing lateral surfaces, themounting surface and first and second lateral surfaces forming first andsecond lateral edges, respectively, a plurality of power switchingdevices mounted side by side to the mounting surface to form a singledevice row that extends along the sink length, each device includingintra-converter terminals juxtaposed substantially within a singleconnection plane, each device also including first and second oppositelyfacing linking edges having a device width therebetween, a bracketmember mounted to the sink member and extending past the first lateralsurface, a plurality of capacitors, each capacitor including capacitorconnection terminals, the capacitors mounted to the bracket memberadjacent the sink member with the capacitor terminals substantiallywithin the connection plane and a linkage assembly including a pluralityof conductors that link the capacitor terminals to the intra-converterterminals to form a power conversion topology.

In some embodiments the sink member forms at least one internal channelthat extends substantially along the entire sink length and an inlet andan outlet that open into opposite ends of the channel and, wherein, theconverter configuration is juxtaposed so that the channel issubstantially vertically oriented. More specifically, the channel inletmay be substantially vertically below the channel outlet.

These and other objects, advantages and aspects of the invention willbecome apparent from the following description. In the description,reference is made to the accompanying drawings which form a part hereof,and in which there is shown a preferred embodiment of the invention.Such embodiment does not necessarily represent the full scope of theinvention and reference is made therefore, to the claims herein forinterpreting the scope of the invention.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

FIG. 1 a is a schematic diagram of a rectifier configuration andcorresponding controller while FIG. 1 b is a schematic diagram of aninverter configuration;

FIG. 2 is an exploded perspective view of a converter assembly accordingto one embodiment of the present invention;

FIG. 3 is an exploded perspective view of the heat sink member andswitch packages of FIG. 2;

FIG. 4 is a side plan view of an assembled configuration consistent withFIG. 2;

FIG. 5 is a bottom plan view of the conversion configuration of FIG. 4;

FIG. 6 is a plan view of the body member of the heat sink member of FIG.3 and, in particular, showing the surface of the body member in which acoolant channel is formed;

FIG. 7 is similar to FIG. 6, albeit illustrating a second embodiment ofthe body member;

FIG. 8 is similar to FIG. 6, albeit illustrating yet one otherembodiment of the body member; and

FIG. 9 is a flow chart according to one aspect of the present invention.

DETAILED DESCRIPTION OF THE INVENTION

Referring now to the drawings where in like numerals correspond tosimilar elements throughout the several views and, more specifically,referring to FIGS. 1 a and 1 b, the present invention will be describedin the context of exemplary motor control system 10 including arectifier assembly generally illustrated in FIG. 1 a which feeds aninverter assembly generally illustrated in FIG. 1 b where each of therectifier and inverter are controlled by a controller 22. As known inthe controls industry, rectifier (FIG. 1 a) receives three-phase ACvoltage on input lines 12, 14 and 16 and converts that three-phasevoltage to a DC potential across positive and negative DC buses 18 and20, respectively. The DC buses 18 and 20 generally feed the inverterconfiguration (see again FIG. 1 b) which converts the DC potential tothree-phase AC voltage waveforms that are provided to a three-phase loadvia first, second and third inverter output lines 24, 26 and 28,respectively.

The rectifier assembly includes twelve separate switching devicesidentified by numerals 30-41. The switching devices 30-41 are arrangedbetween the positive and negative DC buses 18 and 20, respectively, toprovide six separate rectifier legs. Each rectifier leg includes twoseries connected switching devices that traverses the distance betweenthe positive and negative DC buses 18 and 20, respectively. For example,a first rectifier leg includes switches 30 and 36 that are in seriesbetween positive bus 18 and negative bus 20, a second rectifier legincludes switches 31 and 37 that are series connected between buses 18and 20, a third rectifier leg includes switches 32 and 38 that areseries connected between buses 18 and 20, and so on. The nodes betweenswitches in each rectifier leg are referred to as common nodes. Onecommon node between switches 32 and 38 is identified by numeral 46.

Each of input lines 12,14 and 16 is separately linked to two differentcommon nodes. For example, as illustrated, line 14 is linked to commonnode 46 between switches 32 and 38 and is also linked to the common node(not numbered) between switches 33 and 39. In a similar fashion, inputline 12 is linked to the common node between switches 34 and 40 and alsoto the common node between switches 35 and 41 while line 16 is linked tothe common node between switches 30 and 36 and to the common nodebetween switches 31 and 37. In FIG. 1 a (and also FIG. 1 b describedbelow) switch emitters, collectors and gates are identified via E, C andG labels, respectively, with the collectors and emitters of switches 30and 36 qualified by “1” and “2” sub-labels (e.g., E1, E2, C1, C2), todistinguish those emitters and collectors for additional explanationbelow.

A control bus 48 which represents a plurality of different control lineslinks controller 22 separately to each one of the rectifier switches30-41 for independent control. Controller 22 controls when each of theswitches 30-41 turns on and when each of the switches 30-41 turns off.Control schemes that may be used by controller 22 to convert thethree-phase voltages on lines 12, 14 and 16 to a DC potential across DCbuses 18 and 20 are well known in the conversion art and therefore willnot be described herein detail. Rectifier legs that have their commonnodes (e.g., 46) linked to the same input line are controlled in anidentical fashion by controller 22. For example, referring still to FIG.1 a, each of switches 32 and 33 would be turned on and turned off at thesame time by controller 22 and each of switches 38 and 39 would beturned on and turned off at the same times by controller 22 as thecorresponding rectifier legs have the same common node 46 linked to line14.

In addition to the components described above, the rectifierconfiguration illustrated in FIG. 1 a also includes capacitors betweenDC buses 18 and 20 which are collectively identified by numeral 50.Although only two capacitors are illustrated, it should be appreciatedthat a larger number of capacitors would typically be employed in anytype of rectifier configuration. Capacitors 50 reduce the ripple in thepotential between lines 18 and 20 as well known in the art.

Referring now to FIG. 1 b, the inverter configuration illustrated, likethe rectifier configuration of FIG. 1 a, includes twelve separateswitching devices identified by numerals 61-72. The switching devices61-72 are arranged to form six separate inverter legs. Each inverter legincludes a pair of the switching devices 61-72 that is series arrangedbetween the positive DC bus 18 and the negative DC bus 20. For example,a first inverter leg includes switches 61 and 67 series arranged betweenbuses 18 and 20, a second inverter leg includes switches 62 and 68series arranged between buses 18 and 20, a third leg includes switches63 and 69 series arranged between buses 18 and 20, and so on.

Common nodes between inverter leg switch pairs are referred tohereinafter as common nodes. In FIG. 1 b, an exemplary common nodebetween switches 61 and 67 is identified by numeral 80. In theillustrated embodiment, each output line 24, 26 and 28 is linked to twoseparate inverter leg common nodes (e.g., 80). For example, output line28 is linked to common node 80 between switches 61 and 67 and is alsolinked to the common node (not illustrated) between switches 62 and 68.Similarly, output line 26 is linked to the common node between switches63 and 69 and also to the common node between switches 64 and 70 whileoutput line 24 is linked to the common node between switches 65 and 71and is also linked to the common node between switches 66 and 72.

The control bus 48 linked to controller 22 is also linked separate toeach of the inverter switches 61-72 to independently control the turn onand turn off times of those switches. As in the case of the rectifierswitches of FIG. 1 a, controller 22 controls the switches of theinverter legs that have common nodes linked to the same output line inan identical fashion. To this end, referring still to FIG. 1 b, becausethe common nodes (e.g., 80) corresponding to the first inverter legincluding switches 61 and 67 and the second inverter leg includingswitches 62 and 68 are both connected to output line 28, the first andsecond inverter legs are controlled in a similar fashion so that each ofswitches 61 and 62 is turned on and turned off at the same times andeach of switches 67 and 68 are turned on and off at the same times.

Referring to FIGS. 1 a and 1 b, the rectifier-inverter configurationincludes commonly controlled switches so that the configuration canhandle relatively high currents that may otherwise destroy the types ofdevices employed to configure the converters. In this manner relativelyless expensive switches can be used to construct the converter assembly.The switches 30-41 used to configure the rectifier are typicallyidentical and the switches 61-72 used to configure the inverter aretypically identical. Depending on the configuration design, switches30-41 may or may not be identical to switches 61-72.

Referring still to FIGS. 1 a and 1 b, switch manufacturers often providepower switching devices in prepackaged modules suitable to constructinverters and rectifiers. To this end, often, a complete 6-switch bridgewill be provided as a separate and unique switching power package.Hereinafter it will be assumed that the 24 switches that comprise therectifier and inverter in FIGS. 1 a and 1 b are provided in fourseparate 6-switch bridge packets where the first switching packageincludes switches 30, 31, 32, 36, 37 and 38, the second switch packageincludes switches 33, 34, 35, 39, 40 and 41, the third switch packageincludes switches 61, 62, 63, 67, 68 and 69 and the fourth switchpackage includes switches 64, 65, 66, 70, 71 and 72. Unless indicatedotherwise, hereinafter, the first, second, third and fourth switchpackages will be identified by numerals 90, 92, 94 and 96, respectively.Exemplary switch packets 90, 92, 94 and 96 are illustrated in FIG. 2 andare described in greater detail below.

Referring now to FIG. 2, an exploded perspective view of an exemplaryrectifier/inverter converter assembly 100 is illustrated. Configuration100 includes a heat sink member 102, the four-switching modules 90, 92,94 and 96 briefly described above, a bracket member 104, a plurality ofcapacitors collectively identified by numeral 50, a laminated bus bar106 and a plurality of input and output bus bars identified by numerals12′, 14′, 16′, 28′, 26′, and 24′.

Each of switch packages 90, 92, 94 and 96 is similarly constructed andtherefore, in the interest of simplifying this explanation, unlessindicated otherwise, only switch package 90 will be described here indetail. Referring also to FIGS. 3 and 5, package 90 has a generallyrectilinear shape having a length dimension L3, a width dimension W1 anda thickness dimension (not separately labeled). Although not illustratedin any of the drawings, device package 90 is characterized by a devicethickness dimension that will be referred to herein by label T1 that isformed between the mounting or dissipating surface 122 (see FIG. 3) ofthe device and a connection plane defined by the top surfaces of theemitter and capacitor connection terminals that extend from the packagehousing. Package 90 has a first device or first linking edge 130 and asecond device or second linking edge 132 that face in oppositedirections and are separated by device width W1 as illustrated.

Referring still to FIG. 1 a and also to FIG. 2, package 90 includesswitching devices 30, 31, 32, 36, 37 and 38 that are arranged in asingle row relationship where the emitters and collectors for each oneof the switching devices extend from opposite side of package 90 and aregenerally separated by the device width W1. For example, the emitter Eland collector C1 extend from opposite sides of package 90 while emitterE2 and collector C2 for switch 36 extend in opposite directions.Adjacent switches within package 90 have their emitters and collectorsextending in different directions. For example, referring to FIG. 1 aand FIG. 2, switch 36 in FIG. 1 a has its emitter E2 and its collectorC2 extending in directions opposite those of emitter E1 and collector C1of the first switch 30 adjacent thereto in the package 90. Referringstill to FIG. 3, package 90 is designed so that all of the emitter andcollector terminals extend from the package housing within a singleconnection plane.

Hereinafter, unless indicated otherwise, switching device connectionterminals that are linked to any of bus bars 12′, 14′, 16′, 24′, 26′ or28′ will be referred to as inter-converter terminals because thoseterminals are connected through their respective bus bars to componentsoutside the converter configuration. Similarly, any device packageterminals that are linked to laminated bus bar 106 will be referred tohereinafter generally as intra-converter terminals as those terminalsare linked to other components within the converter assembly.

As illustrated and described hereinafter, all of the inter-converterterminals extend from one side of package 90 while all of theintra-converter terminals extend from the opposite side of package 90after the configuration in FIGS. 2 and 4 is assembled. In addition,after assembly, all of the intra-converter terminals for all of packages90, 92, 94 and 96 extend in the same direction and form a connectionline while all of the inter-converter terminals for packages 90, 902,904 and 96 extend in the opposite direction and form a second connectionline (see alignment generally in FIG. 2). The first and secondconnection lines form linking edges of the devices in the packages.

Control ports are provided on a top surface of package 90 to facilitatelinking of control bus 48 to the devices provided within package 90. Anexemplary control port in FIG. 2 is identified by numeral 120.

Package 90 has an undersurface 122 that is in thermal contact with thecomponents inside the package housing that generate heat. Package 90 isdesigned so that surface 122 is substantially flat and can makesubstantially full contact with a heat sink surface when mountedthereto. It should be appreciated that, typically, only a portion ofsurface 122 may generate a relatively large percentage of the totalamount of heat generated by the package and that the primary heatgenerating surface will likely be the central portion of surface 122. Aheat generating segment 124 or dissipating surface of package 92 isillustrated and includes a space that is framed by an outer space 126that surrounds the heat generating space 124. Space 124 generallycorresponds to a space that is in direct contact with the package 90components that conduct current and hence generate heat. Space 124 has adissipating surface width dimension W2 associated therewith.

As best in seen in FIGS. 2 and 3, each package 90 includes a pluralityof small apertures, two of which are identified by number 128, providedthrough the outer space 126 that frames the heat generating segment 124(e.g., see device 92) as illustrated. Apertures 128 are provided tofacilitate mounting packages 90, 92, 94 and 96 to sink member 102.

Referring still to FIG. 2, bus bars 12′, 14′, 16′, 28′, 26′ and 24′ areto be linked to input lines 12, 14, 16 and output lines 28, 26 and 24 inFIGS. 1 a and 1 b, respectively. The linking relationship between busbars and associated lines is highlighted by the bus bars being labeledwith numbers that are identical to the line numbers to which theyconnect followed by a “′” indicator.

Each of input and output bus bars 12′, 14′, 16′, 24′, 26′ and 28′ aresimply steel bars that either have an “L” shape or a “T” shape. Each bar12′, 14′, 16′, 24′, 26′ and 28′ is designed to link input or outputlines to a subset of four of the inter-converter terminals. For example,referring to FIGS. 1 a and 2, L-shaped bus bar 16′ is constructed anddimensioned so as to link together each of the emitter E1 for switch 30,the collector C2 for switch 36, the emitter for switch 31 and thecollector for switch 37 and, to this end, includes four separateapertures for receiving some type of mechanical securing component(e.g., a bolt), a separate aperture corresponding to each one theemitters and collectors to be connect by bar 16′. Each of the other busbars 12′, 14′, 24′, 26′ and 28′ has a construction similar to bus bar16′ and therefore, in the interest of simplifying this explanation, theother bars will not be described here in detail. It should suffice tosay that the bus bars link emitters and collectors among the switchpackages 90, 92, 94 and 96 in a manner that is consistent with theschematics illustrated in FIGS. 1 a and 1 b.

Referring once again to FIG. 3 and also to FIG. 4, heat sink member 102is an elongated and, in the illustrated embodiment, substantiallyrectilinear metallic (e.g., aluminum, copper, etc.) member that extendsfrom a first end 144 to a second end 146, has first and second lateralsurfaces 148 and 150, respectively, that face in opposite directions andextend along the entire length between ends 144 and 146 and alsoincludes a first or first mounting surface 140 and a second oppositelyfacing mounting surface 142. As best illustrated in FIG. 2 (and alsoillustrated in FIG. 6), mounting surface 140 has a width dimension W3that separates the lateral surfaces 148 and 150, respectively and has alength dimension L5. Mounting surface 140 and lateral surfaces 148 and150 form first and second lateral edges 149 and 151, respectively. In atleast one embodiment of the present invention, sink width W3 issubstantially similar to the device package width W1 so that, asillustrated in FIG. 2, device packages 90, 92, 94 and 96 are mounted ina side-by-side single row fashion to be accommodated on mounting surface140.

As best seen in FIG. 3, in at least one embodiment, sink member 102includes two separate components that are secured together. The twocomponents including a body member 160 and a cover member 162. Referringalso to FIG. 5, body member 160 has thickness dimension T2 which isgenerally greater than the thickness dimension (not separatelyidentified) of member 162. Together, body member 160 and cover member162 have a thickness dimension T3.

As illustrated in FIGS. 3 and 6, body member 160 includes a secondsurface 164 opposite mounting surface 140 and forms a cavity 166 thereinwhich extends substantially along the length of body member 160 from thefirst end 144 of the sink member to the second end 146. Cavity 166 has acavity or channel depth Dc and forms a cavity or channel surface 69. Inthe illustrated embodiment, cavity 166 stops short of each of the ends140 and 146, has a cavity length dimension L4 and has a cavity width orreceiving dimension W4. Channel walls are provided on opposite sides ofcavity 166 that have a thickness that is similar to the width dimensionof the framing (i.e., the mounting flange) portion 126 of device surface122 (see FIG. 3). The cavity width dimension W4, in at least someembodiments, is similar to the width dimension W2 of the primary heatgenerating portion or segment 124 of the package dissipating surface122.

Cavity length dimension L4, in some embodiments, is substantiallysimilar to a dimension formed by the oppositely facing edges of thedissipating surfaces of the device packages at the ends of the devicerow attached to the sink member. This dimension will be slightly smallerthan the combined lengths (e.g., L3) of the device packages 90, 92, 94and 96 in most cases. When cavity 160 is so dimensioned, a relativelysmall sink assembly is constructed which still provides effectivecooling to devices attached thereto.

Referring still to FIGS. 3 and 6, within cavity 166, body member 160includes three separate cavity dividing members including a central orfirst dividing member 180 and second and third lateral dividing memberscollectively identified by numeral 182. As its label implies, centraldividing member 180 is positioned centrally within cavity 166 andgenerally divides the cavity into two separate channels. Centraldividing member 180, in the illustrated embodiment, extends such thatits distal end is flush with surface 164 of body member 160. Inaddition, central dividing member 180 extends all the way to a first end184 of cavity 166 but stops short of a second end 186 of the cavity, thesecond end 186 being opposite first end 184.

Each of the second and third dividing members 182 is positioned on adifferent side of central member 180 and each stops short of both thefirst cavity end 184 and the second cavity end 186. In addition, each ofdividing members 182 forms a plurality of openings so that liquidflowing on either side of the member can pass to the opposite side ofthe member. Exemplary openings are identified by numeral 190 in FIG. 3.Like central member 180, in the illustrated embodiment, each of thesecond and third lateral members 182 extends such that its distal end isflush with surface 164 of body member 160.

With openings 190 formed in each of dividing members 182, what remainsof members 182 includes protuberances 290 that essentially break up theflow of coolant through the two channels formed within the cavity 166 asdescribed in greater detail below. In the illustrated embodiment theprotuberances 290 are essentially equi-spaced along the channel lengths.

At the first end 144 of the sink member, in the illustrated embodiment,body member 160 forms an inlet or receiving chamber 192 and first andsecond nozzle passageways 194 and 196, respectively. Inlet chamber 192is formed between end 144 and cavity 166 and is connected to cavity 166on one side of central member 180 by first nozzle passageway 194 and isconnected to cavity 166 on the other side of central dividing member 180by second nozzle passageway 196. Inlet chamber 192 has a relativelylarge cross-sectional area when compared to either of nozzle passageways194 and 196 so that inlet chamber 192 can act as a reservoir forproviding liquid under pressure to cavity 166 through the nozzlepassageways 194 and 196. In the illustrated embodiment, each of thesecond and third lateral dividing members 182 is positioned such thatthe protuberance 290 closest to the inlet nozzle passageway 194 or 196is aligned therewith. At second end 146 of body member 160, body member160 forms a channel extension 210 having a width dimension that is lessthan the cavity width W4.

Body member 160 can be formed in any manner known in the art. One methodfor providing member 160 includes providing the member without cavity166 and scraping metal out of surface 164 to provide a suitable cavity.Another method may be to form body member 160 in a mold. Othermanufacturing processes are contemplated.

Cover member 162 is a substantially planar and rigid rectilinear memberhaving a shape which mirrors the shape of surface 164. Member 162 formsan inlet opening 200 at a first end 204 and an outlet opening 202 at asecond 206. The inlet 200 and outlet 202 are formed such that, whencover member 162 is secured to surface 164, inlet 200 opens into inletchannel 192 and outlet 202 opens into extension 210.

To secure cover member 162 in a hermetically sealed manner to surface164, any method known in the industry can be employed. One method whichhas been shown to be particularly useful in providing a hermetic sealbetween cover member 162 and body member 160 has been to use a vacuumbrazing technique where a bead of brazing material is provided alongsurface 164 of body member 160, cover member 162 is provided on surface164 with the brazing bead sandwiched between members 162 and 160 andthen the component assembly is subjected to extremely high heat therebycausing a brazing function to occur. Other securing methods arecontemplated.

As illustrated, each of body member 160 and cover member 162 form aplurality of apertures (not separately numbered) for receivingmechanical components such as screws, bolts, etc., for mounting devicepackages 90, 92, 94 and 96 and, perhaps, other electronic devices, tothe sink member 102. In addition, body member 160 and/or cover member162 may include other apertures for mounting other converter components(e.g., the bracket described below) to sink member 102 and/or to mountthe sink member 102 within a converter housing for support.

Referring once again to FIG. 2 and also to FIG. 5, capacitors 50 arestandard types of capacitors and, to that end, generally include acylindrical body member having a first end 220 and a second end 222opposite the first end 220 where terminals 224 and 226 extend from eachfirst end 220 and a heat conducting extension 228 (see FIG. 5) extendscentrally from each second end 222. The heat conducting extensions 228,as the label implies, conducts most of the heat from the central core ofthe capacitor. Each capacitor 50 has a length dimension L1 whichseparates the first and second ends 220 and 222.

Referring now to FIGS. 2, 4 and 5, bracket member 104 is, in at leastone embodiment, formed of a heat conducting, rigid material such asaluminum or copper. Bracket member 104 includes a proximal member 230,an intermediate member 232 and a distal member 234. Proximal member 230includes a flat elongated member which has a length substantially equalto the length of sink member 102. Proximal member 230 forms a pluralityof mounting apertures along its length which align with similarapertures (not illustrated) in the surface 142 formed by cover member162 (see again FIG. 3).

Intermediate member 232 forms a 900 angle with proximal member 230 andextends from one of the long edges of member 230. Similarly, distalmember 234 extends from the long edge of intermediate member 232opposite the edge linked to proximal member 230 and forms a 900 anglewith intermediate member 232. The 90° angle formed between intermediatemember 232 and distal member 234 is in the direction opposite the angleformed between proximal member 230 and intermediate member 232 so thatdistal member 234 extends, generally, in a direction opposite thedirection in which proximal member 230 extends. Although notillustrated, distal member 234 forms a plurality of apertures throughwhich the heat dissipating capacitor extension members 228 extend formounting the capacitors 50 thereto. In the illustrated embodiment,distal member 234 forms two rows of substantially equi-spaced aperturesfor receiving the capacitors 50 and arranging the capacitors 50 in twoseparate rows.

Referring again to FIGS. 2, 4 and 5, laminated bus bar 106 includes asubstantially planar member having a general shape similar to the shapeof distal member 134. Although not illustrated, it should be appreciatedby one of ordinary skill in the art that laminated bus bar 106 includesseveral metallic conducting layers where adjacent layers are separatedby insulating layers and wherein different ones of a conducting layersare linked to connecting terminals along one edge of the bus bar.Exemplary connecting terminals are identified by numeral 240 in FIGS. 2and 4.

In addition, although not illustrated, separate vias are provided in anunderside of bus bar 106 which facilitate connection of particularpoints and particular conducting laminations within bar 106 to thecapacitors juxtaposed hereunder when the converter assembly isconfigured. More specifically, referring to FIGS. 1 a and 1 b onceagain, bus bar 106 links various emitters and collectors of theswitching devices 30-41 and 61-72 to the positive and negative DC busesseparated by the capacitors 50 as illustrated. Thus, for example, busbar 106 links the collector of switch 30 to the positive DC bus 18, theemitter of switch 36 to the negative DC bus, the collector of switch 31to the positive DC bus 18, the emitter of switch 37 to the negative DCbus 20, and so on.

It should be appreciated that bus bar 106 can have an extremely simpleand hence minimally expensive construction when used with a sink andswitching device configuration that aligns all intra-converterconnection terminals in a single line and in a single connection plane.Here only a minimal number of laminate layers are required and no viasare required to link to the switching devices as connection terminals240 are within the same plane as the device terminals.

With the converter components configured as described above, aparticularly advantageous converter assembly can be assembled asfollows. First, after the cover member 62 has been hermetically sealedto body member 160, device packages 90, 92, 94 and 96 are mounted tomounting surface 140 of sink member 102 so as to form a single devicerow as illustrated best in FIG. 4. Next, bracket member 104 is securedto surface 142 of cover member 102 so that intermediate member 232generally extends away from sink member 102 and so that distal member234 also extends generally away from sink member 102. Capacitors 50 arenext mounted to distal member 234 with their extending heat dissipatingextensions 228 passing through apertures in member 234 and so that thecapacitors 50 form two capacitive rows as illustrated in FIGS. 2 and 5.

At this point, it should be appreciated that, when bracket member 104 issuitably dimensioned, the connection terminals 224 and 226 that extendfrom the first ends 220 of the capacitors 50 should be within the sameconnection plane as the intra-converter connection terminals extendingtoward the capacitors 50 from each of device packages 90, 92, 94 and 96.To this end, the bracket member 232 should be chosen such that thelength dimension L2 of intermediate member 232, when added to the sinkmember thickness T3 and the device thickness T1 (not illustrated),essentially equals the capacitor length L1. When any of the sink member102, the capacitors 50 or the device packages (e.g., 90) are replaced byother components having different dimensions, the differentlydimensioned components can be accommodated and the capacitor and devicepackage connecting terminals can be kept within the same plane byselecting a bracket member 104 having a different intermediate member232 length dimension L2. Thus, the bracket-sink member assembly rendersthe sink member extremely versatile when compared to previous sinkconfigurations that required multi-plane serpentine coolant paths.

With the capacitor connecting terminals and the intra-converterterminals extending from the device packages within the same connectionplane, planar and relatively simple bus bar 106 is attached to thecapacitor and intra-converter terminals thereby linking the variousterminals to the positive and negative buses 18 and 20 in the fashionillustrated in FIGS. 1 a and 1 b above.

Continuing, the input and output bus bars 12′, 14′, 16′, 24′, 26′ and28′ are next linked to the inter-converter connection terminals asillustrated in FIG. 4 and to link the emitters and capacitors of theswitching devices 30-41 and 61-72 at the common nodes (e.g., 46, 80,etc.) as illustrated in FIGS. 1 a and 1 b.

Referring now to FIG. 5, when all of the components described above aresecured together in the manner taught, an extremely compact converterassembly that requires a relatively small volume is configured. In fact,as illustrated, a space 280 is formed adjacent surface 142 of covermember 162 and adjacent intermediate member 232 where additionalcomponents such as the components required to configure controller 22can be mounted. In some embodiments, at least some of the components ofcontroller 22 will be mounted within cooling space 280 to a secondmounting surface formed by surface 142 of cover member 162 so that themounted components dissipate heat into sink member 102.

Referring again to FIGS. 3 and 6, with cover member 162 secured tosurface 164, when liquid is pumped through inlet 200 and into inletchamber 192, after chamber 192 fills with liquid, the liquid is forcedthrough each of restricted nozzle inlets 194 and 196 into opposite sidesof cavity 166 (i.e., into different halves of cavity 166 where thehalves are separated by central dividing member 180). Because the nozzlepassageways 194 and 196 are restricted, the coolant is forcedtherethrough under pressure which should overcome any pressuredifferential that exists within the opposite sides of cavity 166. As theliquid passes through cavity 166 on its way to and out outlet 202, theliquid heats up between first channel end 184 and second channel end 186and a phase change occurs wherein at least a portion of the liquid, asheat is absorbed, changes from the liquid state the state gas therebyforming bubbles within cavity 166.

Protuberances 290 cause excessive amounts of turbulence within cavity166 as the protuberances 290 redirect liquid along random trajectorieswithin the channels. The excessive turbulence within cavity 166 is suchthat essentially no gas pockets form on the internal surfaces of thecavity 166 or the portion of cover member 162 enclosing cavity 166. Inembodiments where sink member 102 is vertically aligned, bubbles thatform within the cavity float upward under the force of liquid flow andthe force of their own buoyancy. The bubbles proceed out the outlet 202and are thereafter condensed by the cooling system attached thereto asthe refrigerant is cooled.

In FIG. 6, as indicated above, cavity 166 has a width dimension W4 thatis, at least in one embodiment, similar to the width dimension W2 of theheat generating portion of device or package surface 122 (see also FIG.3). Where dimension W2 is smaller, it is contemplated that the dualchannel aspect of cavity 166 may not be required. For example, assumedimension W2 is half the dimension illustrated in the figures. In thiscase, the cavity 166 may be made approximately half the illustrateddimension and hence central member 180 may not be needed.

Experiments have shown that if width dimension W4 is too large and nodividers 180 are provided along the cavity length L4, the turbulencegenerated by the protuberances 290 is substantially reduced. Thus, forinstance, assume member 180 were removed from cavity 166. In this casemuch of the coolant pumped into cavity 166 through passageways 194 and196 would pass relatively calmly through to the outlet end 186 of cavity166. The maximum width of each channel formed within cavity 166 is goingto be a function of various factors including cavity depth, coolantemployed, coolant pressure, the quantum of heat generated by devicepackages mounted to the sink, etc.

It should be appreciated that the protuberances 290 and divider 180within cavity 166 are specifically provided to increase channelturbulence to a level that eliminates gas pockets on channel surfaces.Without gas pockets on the channel surfaces, refrigerant/coolant is insubstantially full contact with all channel surfaces and the temperaturedifferential between the first and second channel ends 184 and 186 issubstantially reduced. The smaller channel temperature differentialmeans that devices mounted to sink member 102 have more similaroperating characteristics as desired.

Referring now to FIG. 9 a method 300 according to one aspect of thepresent invention is illustrated. Here, at block 302, a body member 160(see again FIG. 3) having a limited width dimension W3 and a length L5is provided where the limited width dimension is substantially similarto or identical to the width dimension W1 of the devices to be attachedthereto. At block 304, a cavity is formed in a first surface of the bodymember 160 that extends substantially along the entire length dimensionL5. The cavity is illustrated as 166 in FIG. 3. At block 306, a covermember 162 is provided that is consistent with the teachings above. Atblock 308 an inlet is formed in one of the body member and the covermember. At block 310 an outlet is formed in one of the body member andthe cover member. As above, the inlet and outlet formed should open intoopposite ends of the cavity or channel 166. At block 312, the covermember 162 is hermetically sealed in any manner known in the art to thebody member 160 thereby providing an enclosed channel having only asingle inlet and a single outlet at opposite ends. Continuing, at block314, power switching devices for packages 90, 92, 94 and 96 are mountedto the second or mounting surface with their dissipating widthdimensions substantially parallel to the receiving width dimension W3 ofthe heat sink.

It should be understood that the methods and apparatuses described aboveare only exemplary and do not limit the scope of the invention, and thatvarious modifications could be made by those skilled in the art thatwould fall under the scope of the invention. For example, while the sinkmember 102 is described as being formed of two components otherconfigurations are contemplated. In addition, the protuberances 290 maytake other forms that cause a suitable amount of turbulence within thechannel. For instance, in FIG. 7 another embodiment of the body memberis illustrated. In FIG. 7 components similar to the components of FIG. 6are identified by identical numbers followed by an “a” qualifier. InFIG. 7, instead of providing substantially rectilinear protuberances asin FIG. 6, triangular protuberances 290 a are provided on either side ofmember 280. Moreover, the protuberances may be formed by any channelsurface although forming the protuberances on the surface opposite theheat generating devices (i.e., opposite the mounting surface) increasesthe total surface area proximate the heat generating device that is incontact with the coolant. Furthermore, both the cover and the bodymember may form protuberances and, in some embodiments, the cover membermay form part or all of the cavity 166.

In addition, while the protuberances 290 are illustrated as beingequi-spaced, equi-spacing is not required and, in fact, it may beadvantageous to provide protuberances that cause a greater amount ofturbulence at the outlet end of the channel than at the inlet end as thecoolant at the outlet end could be slightly warmer and hence couldgenerate more problematic vapor bubbles.

Moreover, more than one divider may be provided in a cavity. In thisregard, referring to FIG. 8, another inventive embodiment 160 b of thebody member is illustrated. In FIG. 8 components similar to componentsdescribed above are identified by the same number followed by a “b”qualifier. In FIG. 8 cavity 166 b is twice as wide as the cavity 166 inFIG. 6. Here, to ensure sufficient turbulence to eliminate stagnant gaspockets from the cavity surface, three separate divider members 271, 273and 275 are provided that equally divide cavity 166 b along its width.In addition, separate inlet passageways 251, 253, 255 and 257 areprovided that open from inlet chamber 192 c into each separate channelwithin cavity 166 b and separate lines of protuberances 261, 263, 265and 267 are formed within the separate channels. Thus, the protuberanceconcept has application in wider sink assemblies also although it isparticularly advantageous in long sink assemblies for the reasonsdescribed above.

To apprise the public of the scope of this invention, the followingclaims are made:

1. An electronic converter assembly comprising: a liquid cooled heatsink member having a sink length dimension, at least one mountingsurface and first and second oppositely facing lateral surfaces, themounting surface and first and second lateral surfaces forming first andsecond lateral edges, respectively, the sink member also forming atleast one internal channel that extends substantially along the entiresink length, an inlet and an outlet that open into opposite ends of thechannel; a plurality of power switching devices mounted side by side tothe mounting surface thereby forming a single device row that extendssubstantially along the sink length, each device includingintra-converter terminals that are substantially within a singleconnection plane; a plurality of capacitors, each capacitor includingcapacitor connection terminals, the capacitors linked for support to andadjacent the sink member with the capacitor terminals juxtaposedsubstantially within the connection plane; and a linkage assemblyincluding a plurality of conductors that link the capacitor terminals tothe intra-converter terminals to form a power conversion topology. 2.The apparatus of claim 1 wherein each power switching device includesfirst and second oppositely facing linking edges and wherein theintra-converter terminals form the first linking edge proximate thefirst lateral edge of the sink member.
 3. The apparatus of claim 1further including a bracket member mounted to the sink member andextending past the first surface, the capacitors mounted to the bracketmember for support.
 4. The apparatus of claim 3 wherein the mountingsurface is a first mounting surface and the sink member includes asecond mounting surface that faces in a direction opposite the firstmounting surface and wherein the bracket member is mounted to the secondmounting surface.
 5. The apparatus of claim 4 wherein the bracket memberincludes a proximate member mounted to the second mounting surface, anintermediate member linked to and forming a substantially 90 degreeangle with the proximate member and extending substantially parallel tothe first lateral side of the sink member and generally away from thesink member and a distal member forming a substantially 90 degree anglewith the intermediate member and extending generally away from the sinkmember, the capacitors mounted to the distal member.
 6. The apparatus ofclaim 5 wherein each of the devices includes a heat dissipating surfaceadjacent the mounting surface and is characterized by a device thicknessdimension between the connection plane and the dissipating surface ofthe device, the first and second mounting surfaces are separated by asink thickness, the intermediate member has an intermediate memberlength, each capacitor includes first and second oppositely facing endsand a length dimension between the first and second ends, the capacitorterminals extend axially from the first end of each capacitor and thesecond end of each capacitor is mounted to the distal member and,wherein, the combined sink thickness, device thickness and intermediatemember length is substantially similar to the capacitor lengthdimension.
 7. The apparatus of claim 6 wherein each capacitor has a heatconducting extension that protrudes from the second end of the capacitorand that is in conductive contact with the distal end of the bracketmember.
 8. The apparatus of claim 7 wherein the bracket member is formedof a heat conducting material.
 9. The apparatus of claim 8 wherein thebracket is formed from one of aluminum and copper.
 10. The apparatus ofclaim 8 wherein the linkage assembly includes a substantially planarlaminated bus bar.
 11. The apparatus of claim 1 wherein the linkageassembly links the capacitors and power switching devices together toform an inverter.
 12. The apparatus of claim 11 wherein the linkageassembly links the capacitors and power switching devices together toalso form a rectifier.
 13. The apparatus of claim 2 wherein each devicealso includes inter-converter connection terminals that form the secondlinking edge and the inter-converter connection terminals are adjacentthe second lateral edge of the sink member and wherein theinter-converter terminals are juxtaposed within the connection plane.14. The apparatus of claim 2 wherein the first and second lateral edgesof the mounting surface form a sink member width and wherein a devicewidth between the first and second linking edges is substantiallysimilar to the sink member width.
 15. The apparatus of claim 1 whereinthe channel inlet is disposed below the channel outlet.
 16. Theapparatus of claim 15 wherein the channel inlet is substantiallydirectly vertically below the channel outlet.
 17. The apparatus of claim16 further including extension members that extend into the channelthereby increasing turbulence in liquid pumped from the inlet to theoutlet.
 18. The apparatus of claim 3 wherein the bracket member isintegrally formed with the sink member.
 19. The apparatus of claim 5wherein a cooling space is formed adjacent both of the second mountingsurface and the intermediate member and wherein drive control componentsare mounted to the second mounting surface.
 20. An electronic converterassembly comprising: a heat sink member having a sink length dimension,at least one mounting surface and first and second oppositely facinglateral surfaces, the mounting surface and first and second lateralsurfaces forming first and second lateral edges, respectively; aplurality of power switching devices mounted side by side to themounting surface to form a single device row that extends along the sinklength, each device including intra-converter terminals juxtaposedsubstantially within a single connection plane, each device alsoincluding first and second oppositely facing linking edges having adevice width therebetween; a bracket member mounted to the sink memberand extending past the first lateral surface; a plurality of capacitors,each capacitor including capacitor connection terminals, the capacitorsmounted to the bracket member adjacent the sink member with thecapacitor terminals substantially within the connection plane; and alinkage assembly including a plurality of conductors that link thecapacitor terminals to the intra-converter terminals to form a powerconversion topology.
 21. The apparatus of claim 20 wherein the sinkmember forms at least one internal channel that extends substantiallyalong the entire sink length and an inlet and an outlet that open intoopposite ends of the channel and, wherein, the converter configurationis juxtaposed so that the channel is substantially vertically oriented.22. The apparatus of claim 21 wherein the channel inlet is substantiallyvertically below the channel outlet.
 23. The apparatus of claim 22wherein the mounting surface is a first mounting surface and the sinkmember includes a second mounting surface that faces in a directionopposite the first mounting surface, the bracket member is mounted tothe second mounting surface, the bracket member includes a proximatemember mounted to the second mounting surface, an intermediate memberlinked to and forming a substantially 90 degree angle with the proximatemember and extending substantially parallel to the first lateral side ofthe sink member and generally away from the sink member and a distalmember forming a substantially 90 degree angle with the intermediatemember and extending generally away from the sink member, the capacitorsmounted to the distal member.
 24. The apparatus of claim 23 wherein eachof the devices includes a heat dissipating surface adjacent the mountingsurface and is characterized by a device thickness dimension between theconnection plane and the dissipating surface of the device, the firstand second mounting surfaces are separated by a sink thickness, theintermediate member has an intermediate member length, each capacitorincludes first and second oppositely facing ends and a length dimensionbetween the first and second ends, the capacitor terminals extendaxially from the first end of each capacitor and the second end of eachcapacitor is mounted to the distal member and, wherein, the combinedsink thickness, device thickness and intermediate member length issubstantially similar to the capacitor length dimension.
 25. Theapparatus of claim 20 wherein the bracket member is formed from one ofaluminum and copper.
 26. The apparatus of claim 20 wherein the linkageassembly includes a laminated bus bar.
 27. The apparatus of claim 20wherein the linking assembly links the capacitors and power switchingdevices together to form both a rectifier and an inverter.
 28. Theapparatus of claim 20 wherein the first and second lateral edges of themounting surface form a sink member width and wherein a device width issubstantially similar to the sink member width.
 29. An electronicconverter assembly comprising: a liquid cooled heat sink member having asink length dimension and at least one mounting surface, the sink memberforming at least one internal channel that extends substantially alongthe entire sink length and an inlet and an outlet that open intoopposite ends of the channel; and a plurality of power switching devicesmounted to the mounting surface; wherein, the assembly is juxtaposedsuch that the inlet is substantially vertically below the outlet. 30.The assembly of claim 29 wherein the switching devices are mounted tothe mounting surface in a single device row that extends generallyparallel to the channel.
 31. The assembly of claim 30 wherein at least asub-set of the switching devices are linked together to form aninverter.
 32. The assembly of claim 31 wherein at least a sub-set of theswitching devices are linked together to form a rectifier.